Form for casting concrete poles having longitudinal openings therethrough



July 12, 1966 F N. DEIGAARD 3,260,494

FORM FOR CAS IING CONCRETE POLES HAVING LONGITUDINAL OPENINGS THERETHROUGH Filed March 6, 1964 t 5 Sheets-Sheet 1 FIG 5 7 INVENTOR. FRANK.N. DEIGAARD.

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July 12, 1966 N. DEIGAARD 3,260,494

FORM FOR CASTING CONCRETE POLES HAVING LONGITUDINAL OPENINGS THERETHROUGH Filed March 6, 1964 5 Sheets-Sheet 2 FRANK.N.DEIGAAR D.

W v ww July 12, 1966 N. DEIGAARD FORM FOR CASTING CONCRETE POLES HAVING LONGITUDINAL OPENINGS THERETHROUGH 3 Sheets-Sheet 5 Filed March 6, 1964 (I) at w INVENTOR.

FRANK.N.DE|GAARD.

I viii K. A #1 United States Patent 3 260,494 FGRM FOR CASTING bONCRETE PULES HAVING LONGITUDINAL OPENINGS THERETOUGH Frank N. Deigaard, 7900 (Ioral Way, Miami, Fla. Filed Mar. 6, 1964, Ser. No. 349,881 6 Claims. (Cl. 249-143) This invention relates to apparatus for casting concrete structures of elongated pole-like form, adapted to serve as telephone, telegraph or electric light poles.

The object of the invention is to provide a novel type of apparatus by means of which very strong poles of the character described, having openings formed longitudinally therethro-ugh, may be manufactured with great facility, rapidly, and very economically.

A further object of the invention is to provide a novel type of core for coaction with an external pole-forming form, and means for holding the said core rigidly in place in the form during the packing of the concrete mix in place in the form and around the core.

An additional object of the invention is to provide apparatus by means of which a plurality of poles may be cast simultaneously, in a plurality of forms, and in conjunction With a common tensioning means by which prestressed cables may be incorporated in the finished poles.

Other advantages of the invention will be best understood by reference to the accompanying drawings, in which:

FIGURE 1 is a side elevation of the complete form and associated parts;

FIG. 2 is a side view of the core, hereinafter described, with pants btFOkGIl away;

FIG. 3 is a transverse section through the form on line 3--3 of FIG. 1;

FIG. 4 is a fragmentary sectional view of the core at one end thereof;

FIG. 5 is a detail sectional view of the core at an intermediate point in the length of the same;

FIGS. 6 and 6A show a detail sectional view of the core at the small end of the same;

FIG. 7 is a sectional perspective view of the form at the end thereof adjacent the hydraulic tension-applying mechanism;

FIG. 8 is an inner face view of one of the end plates of the form;

FIG. 9 is a perspective view of the apparatus illustrating an anchoring structure for the fixed end of cables to be tensioned by the structure of FIG. 7;

FIG. 10 is a diagrammatic vie-w showing how a plurality of poles may be made simultaneously by the use of several corresponding forms disposed along a common base but all served by the same tensioning apparatus, and

FIG. 11 is a transverse sectional view of guiding means for the cables, as hereinafter described.

Like numerals designate corresponding parts in all of the figures of the drawing.

In the drawings, 5 designates an elongated, very heavy base. This base is of such length that several concrete poles may be cast simultaneously in a plurality of identical forms, disposed end to end along the base in exact alignment with each other. See FIG. 10. This base is preferably made of concrete and partially embedded in the ground. This positioning of the base aids in imparting to it complete immobility.

The base has a multiplicity of transverse openings 6 formed through it, for a purpose hereinafter described. Concrete poles of the character described are preferably substantially square in cross section, and have a central opening formed longitudinally through them for the passage of wires which conduct electricity through the poles.

The poles commonly employed vary in length from 25 3,269,494 ?atenteci July 12, 1966 'ice to 45 feet, and forms of the correct length are used according to the length of the pole to be cast.

The pole-forming structure consists of an external concrete-receiving form and a central core, which serves to form a Wire-receiving conduit through the length of the pole. The external forms consist of vertical side plates 7 and a bottom plate 8, these plates extending the full length of the form.

The bottom plate is completely separate from the side plates, and the bottom plate rests upon elongated channels 9, said channels, in turn, resting upon base 5. Elongated, L-shaped angles 10 comprise the vertical portions 11 and the horizontal portions 12. Bolts 13 serve to bind the vertical portions against the outer faces of the channels 9, and when these bolts are tightened, the horizontal portions 12 of the angles act to bind the bottom plate 8 securely against movement, said horizontal portions 12 overlapping and bearing upon the upper face of the outer edge portions of bottom plate 8.

The top portions of the side plates are secured to elongated channels 14, of inverted U-shape, the top edges of the side plates lying flush with the upper faces of the channels 1 4. The side plates are stiffened by short sections of I-beams 1-5, to which the side plates are secured. These stiffening members 15 are disposed at short intervals along the length of the form, and they haw vertical tubular members 16 fixedly secured to their outer faces. The members 16 are also fixedly secured, as by welding or otherwise, to the outer sides of the horizontal channel 14.

Yokes, comprising vertical legs 17 and a transverse lifting bar 18, are utilized to tie the two side plates together during the pole-forming operation. At that time, the legs 17 pass downwardly through the tubular members 16, and their lower ends rest upon the top of the base 5. The lifting bar 18 provides means by which the legs may be pulled upwardly out of the members '16 when the side plates are to be removed.

The lifting bar 18 is designedly made sufficient-1y wide and rigid to hold the legs 17 in exact parallelism with each other. Thus, when the legs 17 are in place in the tubular members 16, the side plates will be held exactly vertical, and in parallelism with each other.

It is the usual practice in the formation of concrete poles utilized by public utility organizations, to chamfer the edges of the poles, as indicated at 19 in FIG. 7. The chamfering of these edges not only adds to attractiveness of design of the poles, but it reduces the degree of damage to the poles and to automobile or other vehicles which may come into forcible collision with the poles.

In many cases of collision, the contact of the vehicle with the pole in a sliding one, as the drive of the vehicle attempts to swing away from the pole. However, when the collision occurs with a pole chamfered as described, there is no sharp edge of the concrete to be chipped or broken away.

Also, there is no sharp edge of concrete to bite forcibly into the metal of the colliding automobile. Where a sharp edge is present, in a pole that is not chamfered, the biting of the sharp edge of the pole into the metal rips away and cuts automobile fenders, and strips away door handles and the chrome trim of the colliding automobile.

To suitably chamfer the edge of the pole, elongated triangular fillets 20 are secured along both the upper and lower edges of the side plates at the inner sides of said plates (PEG. 3). These fillets present surfaces lying at angles of 45 at their points of contact with the pole being cast.

After a pole has been cast and the side plates are to be removed, the presence of the lower fillets 20 aids in facilitating the removal of the side plates. At this time, the loosening of the bolts 13 permits the angles 10 to move slightly outward, and this in turn permits a slight outward movement of the fillets away from the cast pole. Then, when the legs 17 are withdrawn from the tubular members 16, the channels 14 and the attached side plates may be rocked slightly outward, and then lifted free of the pole that has been cast.

The users of elongated concrete poles of the character described require that these poles be made very strong, and that they be so reinforced internally that even these relatively brittle poles cannot snap off under lateral strains imposed thereon. This is especially important in areas where hurricanes or other atmospheric disturbances, with high wind velocities and flying debris, may be expected.

It is, therefore, common practice to embed longitudinally extending, spirally wound steel cables in the concrete of the poles. The apparatus of this invention includes means for locating highly pre-stressed, spirally wound, and consequently spirally grooved, steel cables in the forms, before the placing of any concrete in the forms.

The ends of the forms are closed by substantially square, rigid plates 21, the inner faces of which along the top and are bounded along their tops and sides by fillets 22. The plates 21 bear against the ends of the side plates 7, and the fillets 22 enter between the side plates and match up with the ends of the fillets 20 (FIG. 4), so that the end plates are securely held against lateral shifting. Like fillets 22a, secured to bottom plate 8, lie against the lower inner faces of the end plates and match up with the longitudinal fillets 20, of the side plates.

The number of cables which may be embedded in the finished pole way vary, but they should be so equally spaced around the center of the pole that a complete balance of strain is achieved.

In the present instance, I have illustrated four of the reinforcing cables 23, which pass through openings 23 in the end plates. In FIG. 9, it is illustrated that these cables pass between the pairs of bearing plates 24 and 25 and have holding clamps, or chucks, 26 applied to their ends, the inner ends of which chucks bear against the edges of the pairs of plates 24 and 25.

This anchors the cables at the ends shown in FIG. 9, and an endwise pull may be imparted to the cables to prestress them by a powerful hydraulic jack structure illustrated in FIG. 7. In that figure, the hydraulic cylinder 27 has its opposite ends connected to a source of pressure fluid supply by means of pipes, indicated at 28. A very stout steel head 29 is embedded in the concrete base and serves as an anchor for the cylinder 27, said cylinder being connected to a rod 30, which passes to and through a bearing plate 31, which lies at and bears against the rear face of head 29. The operating plunger rod 32 of the hydraulic jack passes through and is secured to the end wall 33 of a box-like connector 34.

A cable to be put under tension, indicated at 23* passes through a notch 35, formed in the other end wall of the connector 34, and has one of the cable clamps, or chucks, 26 applied thereto. These cable clamps, or chucks, are of conventional form, and they are made in such manner as to grip a cable in such a way that they will prevent any slipping of the cable with respect to the clamps.

These clamps are well known in the art and are the subject of U.S. Patent 3,049,775. They will resist slippage under a pull of well in excess of twenty thousand pounds, and in the manufacture of poles by this invention, the cables '23 are put under a tension of approximately twenty thousand pounds.

The cable being tensioned passes through properly placed openings formed in a stout bearing plate 35 said bearing plate in turn resting and bearing against the rear face of a heavy abutment 35 of inverted U-shape, the legs of which are anchored in the base 5. The plate 35 is held in place by stout metallic straps 35.

After the cables have been tensioned, clamps 35 are applied to them, in a position to bear against the outer face of plate 35 Then the clamp within the box-like connector may be released, and the hydraulic jack structure may be used to stretch the additional cables in the same way.

After the pole has been cast and the concrete has hardened to such a point that the engagement of the concrete with the cables will be such as to prevent any movement of the cables within the concrete, the cables may be cut at a point between the abutment 35 and the end plate of the form, and the dismantling and removal of the side plates to expose the sides of the finished pole may go forward.

An additional cable 36 is disposed centrally within the form, passes through central openings 37 of the end plates, has a tension of approximately five thousand pounds imposed thereon, and is held in this tensioned condition during the casting of the pole, by the application of clamps 26, of the character described, this cable 36 extending to the same point in FIG. 9 as the remaining cables, and being there held by one of the clamps 26. This central cable 36 also extends to and through plate 35 and has one of the clamps applied thereto in the rear of said plate, in a manner described with respect to the cables 23.

The poles to be manufactured taper from a large end A, in FIG. 7, to a small end B, in FIG. 9, and the end plates 21 have four openings formed through them for the passage of the outermost cables. The centrally disposed cable is utilized as the mounting for the core illustrated in FIG. 2, and which core serves to form the central wire-receiving opening 37 in the finished pole.

The core, which extends from end plate to end plate 21 and is supported wholly upon the cable 36, consists of a plurality of telescopic sections. These may vary in number, but in the case of a 35 foot pole, there would be about seven of these sections, each slightly over five feet in length.

They vary in diameter, from a section that is but slight- -ly larger in internal diameter than the cable itself, to a section of much greater diameter at the larger end of the core. However, the larger ends of the telescopic sections are provided internally with annular members 38, these members having central openings through them which fit and slide along the cable.

Thus, all sections of the core are accurately centered with respect to the cable, and the cable itself is accurately centered with respect to the form, and yet no means need be provided for the support of the form other than the pre-stressed center cable. By pre-stressing the cable, as described, said cable is rendered exceedingly rigid and highly resistant to lateral displacement of the core, as the concrete constituting the pole is filled in around the core.

The core sections may be made of any one of a large number of materials. I have found Fiberglas to be useful in this relation. It is light in weight, very strong, and renders the core, as a whole, easily handled and collapsed. The core sections may, if desired, be wrapped with an oiled paper, or otherwise lubricated, to facilitate jarring each section loose from the surrounding concrete in the pole and collapsing it into the next larger section of the core.

The mouths of the openings through the annular members are flared, as at 38 This is for the purpose of permitting the ready entrance of an elongated rod through the core after the concrete 0f the pole has set, or hardened, and the central cable and end plates of the form have been removed. 7

By passing an elongated rod through the core and out of the small end of the core, and then applying a nut to such rod, the core may be pulled out of the pole. In doing this, the rod may be given a series of jerks to cause the nut on its end to bump the first section of the core loose from its encircling concrete wall, the same bumping and loosening action being continued along the full length of,

33 the core, as the several annular sections at the ends of the sections bump against the like annular members of the next larger sections.

It should be noted that by this arrangement, only a single core part, of about five feet in length, has to be jarred loose at any one time. If a continuous core, of approximately 35 feet in length were used, instead of this collapsible core, it would be necessary to jar the whole core loose at one time, and this is difiicult to do.

Referring now to FIG. 9, it will be seen that the plates 24 and 25 have projecting portions 24 and 25 and that these bear against the relatively wide and stout transverse member 39 of an abutment which, as a whole, is designated 40. This abutment comprises the transverse member 39, vertical side portions 41, and vertical brace plates 42. The brace plates are attached to the elongated plates 43, which plates have openings 44- formed through them for the passage of the ends of one or more rods 45.

These rods pass through the transverse openings 6 of base 5, and they bind the abutment 45 in fixed position with respect to the base. However, the strain imposed upon this abutment by a plurality of steel cables, each under approximately twenty thousand pounds stress, is so great that an additional bracing means is provided, which consists of a transverse plate 46, which lies in front of the abutment and bears against the front face of said abutment. This plate 46 is attached at its ends to inclined rods 47, and these rods are in turn connected to stout members having the general cross-sectional shape of railroad rails.

The base portions of these rails 48 are secured by bolts 49 to the base 5, nuts 50 holding the rods securely in place. The openings 6 of the base are so positioned with respect to the spacing between bolts 45 and 49 that the abutment may be positioned at will, whether for the purpose of varying the length of a pole to be cast, or for positioning said abutment with respect to an additional pole that is to be cast, as illustrated in FIG. 10.

It is to be noted that the forms herein described are supported upon, but he wholly above, the base. Thus, they are rendered more or less flexible and elastic. This makes it possible to successfully use vibrating machines to cause a firm settling of the concrete into the forms and among and about the several cables.

In some known constructions, forms for elongated poles have been used in which the forms have consisted of trough-like elements formed directly in heavy concrete bases, said troughs being then lined with metal. This prevents the successful use of a vibrating machine, which acts by impacting the concrete into place by its vibration, and makes it necessary for the concrete to be thrust into place by hand tools, in bringing about its proper settlement and engagement with the cables of the core.

By mounting the forms wholly above the concrete base and permitting them to have a limited capacity for vibration, a vibrating machine placed upon the forms and resting upon the channels 14 or the bars 18 of the yokes will effioiently vibrate the Whole fluid mass into condensed and impacted form around and about the core, and into close engagement with the spiral grooves upon the faces of the spirally wound cables. This effects marked economies over filling in the concrete and pushing it into place with hand tools.

As previously stated, the poles to be manufactured taper in their length, a 35-foot pole being approximately 12 inches square at its large end and only 6 inches square at its smaller end. Consequently, when it is desired to cast a plurality of poles simultaneously, in forms disposed in longitudinal alignment, the large end of one pole may be disposed in proximity to the large end of another pole, and thus no straight line pull can be had from a hydraulic jack unless means are provided for guiding the cables which are to extend through all of the poles.

In FIG. 11, I have illustrated guiding means disposed between the several forms which will guide the cables being tensioned into positions of exact parallelism with the longitudinal axis of the several forms. These guiding means are designated 51 as a whole, and they comprise a stout transverse Lbeam 51 a vertical wall 52 of which has openings 53 formed therethrough for the passage of the several cables.

When the cables are to be guided into the lowest end of a pole-forming form, a transverse I-beam like 51 having its openings 53 at a low point will be used, and when the cables are to be guided into a form, the axis of which is at a higher level, then an I-beam guide element 51 having its openings 53 at a higher lever, will be employed.

The ends of the I-bea-m 51 are secured to vertical plates 54, which have sleeves 55 formed upon their outer faces. Bolts 56, carrying nuts 57, pass through the sleeves 55, and the head ends 56' of said bolts engage beneath web portions 57 of rails 58. Angle plates 59 carry the rails and are themselves held to base 5 by bolts 60, which bolts pass through some of the openings 6 of the base. =By removing the nuts 57 from bolts 56, one guiding I-beam may be substituted for another when the guiding level is to be changed.

The core-guiding cable 36 passes, as stated, through the central openings 37 in the end plates 21, and after the cable has been tensioned but before it has been released, conventional cable clamps 61 hold the end plates against movement with respect to the ends of the side plates of the form and prevent ieakage of the fluid concrete mixture out of the ends of the form.

While the invention has been described as used in the manufacture of concrete poles, it will be understood that the elements described may be used wit-h equal facility in the manufacture of poles from any material which is initially fluid enough to enter the forms and to flow around the core and is of a nature to securely bond with the spirally wound surfaces of the highly tensioned outside cables, and thereafter hardens.

When using concrete as the pole-forming material, a quick setting concrete is employed. Since, to meet the demands of the purchasers of the poles, it is necessary to impose tensions of almost twenty thousand pounds upon the cables, it is preferred to tension the cables one at a time, and it is to facilitate this that the box-like connector 34 is employed.

This connector is of such manufacture that it is very strong. It is held in place on the operating plunger 3-2 by a nut 32 and by loosening this nut, the connector 34 may be swung as a whole around the projected axis of the operating plunger. This, with the vertical slotting of the front wall of the connector at 35, permits a cable being tensioned to be axially aligned with the plunger, and a straight line pull may be imposed upon the cable.

While the manufacture of poles of from 24 to 45 feet has been referred to, it is a fact that poles of up to feet are sometimes required by the trade, and the structure disclosed herein is adapted to manufacturing poies of widely varying lengths and thicknesses. In the case of these larger poles, the sizes and numbers of the reinforcing cables may be changed to fit differences in poles and the length of the core sections may likewise be varied to fit the length of the pole being cast.

-It is to be understood that the invention is not limited to the particular structures shown and described, but that it includes within its purview whatever changes fairly come within either the terms or the spirit of the appended claims.

I claim:

1. Apparatus for casting an elongated pole having a longitudinal channel therein from material such as concrete, which material is initially flowable and subsequently hardens into a solid mass, said apparatus comprising an elongated form having opposite side walls, a bottom wall and end walls, into which form the material to be cast is introduced from the top of the form, a strong metal cable stretched longitudinally through the form and through the end walls of the form, and a core consisting of a plurality of telescoping sections of substantially equal length and having substantially cylindrical internal faces of varying diameters, the smallest section having an internal diameter slightly larger than said cable, each of the other sections having an annular support member at its inner end extending annularly around a central opening slightly larger than the cable and through which opening said cable is adapted to be stretched so that said core is slidably supported on said cable at each of said support members, the outer end of each of said other sections overlapping and slidably engaging the outer face of the next smaller section of the core for slidable support thereby in central alignment in said form.

2. Apparatus for casting an elongated concrete pole, which pole has an opening extending longitudinally through the pole throughout the major portion of its length, said apparatus comprising a form consisting of elongated side walls, a bottom wall and end walls, one at least of said end walls being removable, a plurality of cables extending longitudinally through the form, means for highly tensioning all of said cables during a concrete filling and setting operation, one of said cables passing centrally and longitudinally through the form, a core composed of a plurality of telescopically engaged sections, each section having telescopically inner and outer ends and annular support members in its inner end with a central opening for said central cable to pass therethrough, said sections being slidably mounted in extended relation upon said central cable for supporting them at each annular member in central alignment in said form and serving collectively to form the central hollow space in the pole when the form is filled with concrete.

3. An apparatus for simutaneously forming a plurality of elongated concrete poles each of which has a central longitudinal opening therein which extends throughout the major portion of the length of said pole, said apparatus comprising a stout, elongated base, a plurality of forms disposed in a row, end-to-end, along said base, said forms comprising side and end walls, said end walls having openings formed therethrough, one of which openings is centrally disposed with respect to the forms, a group of strong cables stretched longitudinally through all of the forms, one of the cables of the group extending centrally and axially through all of said forms, anchoring means for anchoring all of said cables to the base at one end of the row of forms, and a power jack located at that end of the row of forms remote from said anchoring means, means for connecting the group of cables to the power jack for highly tensioning all of said cables, and a core consisting of a plurality of telescopic sections in each form, which sections are slidably mounted upon said central cable, each section having a support member at its inner end with a central opening for slidable support on said cable, said core in extended position being centrally aligned in its form and serving to form the central longitudinal hollow space in the pole when the concrete is poured into the form and around said core.

4. Apparatus as recited in claim 3 wherein the forms taper from end-to-end to thereby form externally tapering concrete poles, the larger ends of the said tapering forms being disposed toward the larger ends of the next adjacent forms and the smaller ends toward the smaller ends of adjacent forms in said row of forms.

5. Apparatus as recited in claim 4, and guide means disposed to guide all of the cables between adjacent forms into said forms in parallelism with each other and in parallelism with the longitudinal axis of each of the forms.

6. Apparatus as recited in claim 5, and means for adjusting said guide means vertically and for holding said guide means in such Vertically adjusted position.

References Cited by the Examiner UNITED STATES PATENTS 832,594 10/1906 Collier 25-118 877,008 1/1908 Skinner 25-118 925,793 6/1909 Jones 25-121 973,323 10/1910 Vreeland 25-121 1,025,508 5/1912 Caldwell 25-121 1,390,104 9/1921 Emmrich 25-128 1,856,589 5/1932 Peterson et al 25-118 2,153,741 4/1939 Cobi 25-128 2,445,894 7/ 1948 Troiel 25-118 2,590,478 3/1952 Weinberg 25-118 2,695,754 11/1954 Karig 25-118 2,949,655 8/1960 Berumen et al. 25-118 2,966,717 1/1961 Fuller et al 25-118 3,023,475 3/1962 Yerby et al. 25-118 3,032,852 5/1962 Hanson 25-32 3,049,786 8/1962 Jones 25-118 3,092,886 6/1963 Dykeman et al 25-118 3,116,530 1/1964 Francis 25-118 3,146,508 9/1964 Berliner et al. 25-118 FOREIGN PATENTS 160,370 1/1955 Australia. 184,159 8/ 1936 Switzerland. l

J. SPENCER OVERHOLSER, Primary Examiner.

MARCUS U. LYONS, G. A. KAP, M. V. BRINDISI,

Examiners. 

1. APPARATUS FOR CASTING AN ELONGATED POLE HAVING A LONGITUDINAL CHANNEL THEREIN FROM MATERIAL SUCH AS CONCRETE, WHICH MATERIAL IS INITIALLY FLOWABLE AND SUBSEQUENTLY HARDENS INTO A SOLID MASS, SAID APPARATUS COMPRISING AN ELONGAGED FORM HAVING OPPOSITE SIDE WALLS, A BOTTOM WALL AND END WALLS, INTO WHICH FORM THE MATERIAL TO BE CAST IS INTRODUCED FROM THE TOP OF THE FORM, A STRONG METAL CABLE STRETCHED LONGITUDINALLY THROUGH THE FROM AND THROUGH THE END WALLS OF THE FORM, AND A CORE CONSISTING OF A PLURALITY OF TELESCOPING SECTIONS OF SUBSTANTIALLY EQUAL LENGTH AND HAVING SUBSTANTIALLY CYLINDRICAL INTERNAL FACES OF VARYING DIAMETERS, THE SMALLEST SECTION HAVING AN INTERNAL DIAMETER SLIGHTLY LARGER THAN SAID CABLE, EACH OF THE OTHER SECTIONS HAVING AN ANNULAR SUPPORT MEMBER AT ITS INNER END EXTENDING ANNULARLY AROUND A CENTRAL OPENING SLIGHTLY LARGER THAN THE CABLE AND THROUGH WHICH OPENING SAID CABLE IS ADAPTED TO BE STRETCHED SO THAT SAID CORE IS SLIDABLY SUPPORTED ON SAID CABLE AT EACH OF SAID SUPPORT MEMBERS, THE OUTER END OF EACH OF SAID OTHER SECTIONS OVERLAPPING AND SLIDABLY ENGAGING THE OUTER FACE OF THE NEXT SMALLER SECTION OF THE CORE FOR SLIDABLE SUPPORT THEREBY IN CENTRAL ALIGNMENT IN SAID FORM. 